Brønsted Acid Catalyzed Vinylogous Mannich Reaction

Significance

A catalytic, enantioselective vinyl­ogous Mukaiyama-Mannich reaction of acyclic silyl dienolates and imines is presented. The corresponding δ-amino α,β-unsaturated carboxylic esters are obtained in high yields, with complete regioselectivity and good to very good enantio­selectivities (er up to 96:4). The broad scope of this reaction is shown by employing aromatic, heteroaromatic and one aliphatic, non-enolizable aldimine. This reaction was also performed as a three-component Mannich reaction with aldehyde, amine and silyl dienolate. Here, the obtained Mannich product gave even slightly better results than in the two-component reaction.